Method of making smart cards with an excapsulant

ABSTRACT

A method of making smart cards with an encapsulant ( 23 ) without having a bulge by heat lamination is disclosed. The core material ( 21 ) is cut for the encapsulant ( 23 ), such as a sensor or electronic component and laminated with a bottom layer ( 24 ) to create a cavity ( 22 ). The encapsulant ( 23 ) is introduced in the cavity ( 22 ) and laminated with another layer ( 27 ).

BACKGROUND OF THE INVENTION

This invention relates to a method for making smart cards having acavity for an encapsulant without a bulge.

Smart cards are typically one composite piece of a plastic. It is almostimpossible to access the encapsulated electronic components of smartcards without cutting the cards. Smarts cards are typically tamperresistant and tamper evident.

Smart cards are used as bankcards, ID cards, telephone cards and thelike. Smart cards are usually made by embedding electronic componentsbetween several layers of plastic sheets in a sandwich array. If theelectronic components can withstand high temperature, smart cards aremade by encapsulating them in molten polymeric materials. Recentlysmarts cards are made by encapsulating electronic components inpolymeric materials by a technique commonly known as reaction injectionmolding.

U.S. Pat. No. 6,902,116 describes a method of making smart cards havinga card core with two or more laminated layers. The cavity is milled intoone or more of the layers to receive the electronic circuitry. Thecavity is then filled. The core layers are then laminated together,along with protective overlays. Alternative fabrication methods includeco-extrusion and injection molding.

U.S. Pat. Nos. 6,886,246 and 6,404,643 to Chung describe a method formaking an article having an electronic device embedded thereincomprising a substrate having first and second opposing broad planarsurfaces; mounting an electronic device on the first broad planarsurface of the substrate; and applying a layer of melt-flowable adhesiveof substantially uniform thickness on the first broad planar surface ofthe substrate to cover the electronic device. The article producedthereby has the electronic device encapsulated by the layer ofmelt-flowable adhesive.

U.S. Pat. Nos. 6,241,153 and 6,256,873 describe methods of making smartcards having high quality external surfaces by making use of aprimer/adhesive (and, optionally, anchor hooks) on the lower surface ofan electrical component in order to affix said electrical component to athermosetting material that becomes the core layer of said cards.

European patent 350179 discloses a smart card wherein electroniccircuitry is encapsulated in a layer of a reaction moldable polymericmaterial that is introduced between the card's two surface layers.Similarly European Patent Application 95400365.3 teaches a method formaking contactless smart cards where an electronic module isencapsulated with a polymerizable resin material between upper and lowerthermoplastic sheets.

U.S. Pat. No. 5,399,847 teaches a credit card that is comprised of threelayers, namely, a first outer layer, a second outer layer and anintermediate layer. The intermediate layer is formed by injecting athermoplastic binding material that encases the electronic elements inthe intermediate layer material. The binding material is made of a blendof copolyamides or a glue having two or more chemically reactivecomponents that harden upon contact with air. The outer layers of thissmart card can be made up of various polymeric materials such aspolyvinyl chloride or polyurethane.

U.S. Pat. No. 5,417,905 teaches a method for manufacturing plasticcredit cards wherein a mold tool comprised of two shells is closed todefine a cavity for producing such cards. A label or image support isplaced in each mold shell.

Methods of making smart cards is also disclosed in other patentsincluding U.S. Pat. Nos. 4,339,407, 4,961,893, 5,350,553, 5,423,705,5,498,388 and 5,510,074. All of these prior art methods for making smartcards are usually for encapsulating electronic components or circuitryinside the smart card. Often the electronic components are held in placewith a glue sometimes isotropic thermoset adhesive materials.

Patent application number WO 2004/077097 describes a radiation sensitivedosimeter. The radiation sensitive dosimeter is typically made bysandwiching a radiation sensitive coating or strip between two plasticlayers with a pressure sensitive adhesive.

Radiation sensitive materials, such as diacetylenes (R—C≡C—C≡C—R, whereR is a monovalent group) and processes that can be used for makingradiation sensitive coatings or strips for making Self-indicatingInstant Radiation Alert Dosimeter (referred herein as SIRAD) are listedin patent application number WO 2004/077097 and WO 2004/017095 andreferences cited therein. The encapsulant for making SIRAD cards, apiece of plastic films or plaque of radiation sensitive materials isdescribed in Patent application number WO 2004/077097. The encapsulantfor SIRAD is also referred herein to as “radiation sensitive coating”,“radiation sensitive strip” or “SIRAD strip”. An encapsulant in generalis also referred to as sensor, including radiation sensor.

U.S. patent application No. WO 2004/077097 and WO 2004/017095 describe amethod of making temper resistant SIRAD cards by reaction injectionmolding. This application also mentions that the cards can be made byheat lamination method.

SUMMARY OF THE INVENTION

Provided is a method and its variations of making smart cards byencapsulating an encapsulant in a core material having a cavityessentially the same shape as that of an encapsulant. The core materialwould have the same or close to the same thickness as that of anencapsulant. The core material is then cut having essentially the sameshape or close to that of the encapsulant to create a hole. The hole inthe core material is also referred to herein as a cavity or well. Thecore material is then laminated with a bottom support layer, preferablyby heat lamination method. The encapsulant is then inserted in thecavity and laminated with a top layer, preferably by heat lamination, toseal the encapsulant to make the card. The encapsulant could be anymaterial, such as an electronic device or component, a circuitry, asensor and alike and referred them herein as to encapsulant, element orsensor.

Provided are processes of selecting (1) a core material having thethickness essentially the same as that of the encapsulant and able tobond acceptably strong with top and bottom layers with an adhesive; (2)bottom and top layers having desired thicknesses, transparencies oropaqueness, and ability to bond with the core material with an adhesive,and (3) an adhesive to bond the bottom and top layers with the corematerial. Provided are steps of (1) cutting the core material withessentially the same shape as that of the encapsulant and (2) laminatingwith a bottom layer with an adhesive to create a cavity or well for theencapsulant.

Provided are different methods of creating a cavity in the core materialby processes such as die-cutting and laser-cutting.

Provided is a process of picking up the encapsulant and placing in thecavity.

Provided is a process of applying the top layer over the core layer andencapsulant and laminating with an adhesive.

Provide is a method of production cards on line on a continuous basis

Provided is a method of making SIRAD type cards.

Provided also is a method of making cavity by commonly known as moldprocess where the core material is molded with the cavity.

Provided is a process of molding core layer with cavity and the bottomlayer as one piece.

Provided is a process of molding core layer with cavity and the bottomlayer as one piece and further printed with required information on thebottom and color reference bars on the top.

A particularly preferred embodiment is provided in a multi-layer smartcard with a top layer, a core layer having at least one cavity, anencapsulant in the cavity, a bottom layer and adhesive layers betweenthe top layer and the core layer and between the core layer and thebottom layer.

Another embodiment is provided in a process of making a smart card. Theprocess includes providing a core layer with a cavity; providing abottom layer; laminating the bottom layer to the core layer; insertingan encapsulant is the cavity; and laminating a top layer to the corelayer.

Yet another embodiment is provided in a process of making a smart card.The process includes providing a first layer; providing a second layerwherein the second layer has at least one cavity; providing a thirdlayer; inserting an encapsulant into the cavity; placing the firstlayer, the second layer and the third layer in layered relationship; andfusing the layered relationship to form the smart card.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of different layers and a method usedfor making SIRAD cards.

FIG. 2 is an exploded side view of SIRAD card illustrating thecomponents and manufacture.

FIG. 3 is a cross sectional view of a card with more than one bottomlayers.

FIG. 4 is a schematic presentation of the manufacturing steps for aSIRAD cards.

FIG. 5 is a schematic presentation of a sheet of core layers and sensingstrips for manufacturing dual-sensor SIRAD cards.

FIG. 6 is a schematic presentation of four layers for making dual-sensorSIRAD cards with printing of each layer.

FIG. 7 is a schematic presentation of a preferred process for makingdual-sensor SIRAD cards from four layers.

FIG. 8 is a schematic presentation of five layer cards and methods formaking dual-sensor SIRAD cards with printing on some layers.

FIG. 9 is a schematic presentation of six layers for making dual-sensorSIRAD cards with printing on some layers.

FIG. 10 is a example of printing on a black protective cover of SIRADcard.

FIG. 11 is an example of printing on a core layer for a dual-sensorSIRAD card.

FIG. 12 is an example of printing on the back of the bottom layer for aSIRAD card.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Provided herein is a method for making smart cards and the cardsmanufactured thereby. In order to explain the invention, a radiationsensing strip is used as a encapsulant in the following drawings andTeslin® is used as the core material.

The invention can be best described by reference to the Figures. Thesmart card is also referred to as a device. In the disclosure below theencapsulant is a radiation sensing strip described in PatentApplications Nos. WO 2004/077097 and WO 2004/017095 both of which areincorporated by reference, but it could be any other sensor, electronicdevice or for that matter, any other encapsulant. Similarly, the processis exemplified with making of SIRAD cards but any other type of smartcards can be made using the procedures disclosed below.

A sequence for manufacturing smart cards for monitoring radiation,typically referred to as SIRAD, is illustrated schematically in FIG. 1generally at 10. A pre-printed bottom opaque layer, 11, such as amineral filled PVC is the initial layer as provided at step A. Thepre-printed bottom opaque layer is overlayed with a non-stick releasefilm, 12, at step B. The non-stick layer, 12, also referred to as arelease layer, is required to peel off of the die-cut area for thesensor. A core layer, 13, such as PVC or polyolefins such as Teslin®, amicroporous battery membrane supplied by PPG Industries, Pittsburgh,Pa., is applied by a conventional high temperature, high pressurelamination method of making credit cards which overlays the non-sticklayer, 12 and opaque layer, 11, at step C. The core layer is thendie-cut and peeled off with a sharp object such as a knife to create acavity, 14, for the sensing strip, 15, at step D and the sensing stripis inserted into the cavity at step E. A clear polyester film, 16,having a PSA layer, 17 is laminated over the core layer at step F. Thisprocess for forming a SIRAD card is functional yet the top film with PSAcan be peeled off. The process is tedious, labor intensive, expensiveand difficult to perfect. There is a need for a simpler, less expensiveand less tedious method. An improved method is provided herein.

A preferred method for manufacturing a smart card will be described withreference to FIG. 2 wherein the smart card is shown in exploded viewgenerally at 20. In FIG. 2, the core layer, 21, preferably has a pre-cutcavity, 22, which has approximately the same dimensions as that of theencapsulant, 23. The cavity of the core material is preferably die-cut,however, it can also be made by any other known method such as with alaser cutting, pre-molding or casting the core layer with the cavity.The core layer is then bonded to a bottom layer, 24, preferably by anadhesive layer, 25, such as a pressure sensitive adhesive (PSA) or aheat activated adhesive (HAA). The encapsulant, 23, is then insertedinto the cavity, 22, and laminated with a top layer, 27, by an adhesivelayer, 26, such as a PSA or HAA. The card can then be die-cut to anydesired shape, preferably that of a credit card.

The smart cards can have more than one bottom, core and top layers asshown in FIG. 3. In FIG. 3 the card is generally represented at 30. Thecard comprises a printable layer, 31. Supra the printing layer is abottom opaque layer, 33, with adhesive layers, 32 and 34, on either sidethereof. The adhesive layers bond the bottom opaque layer to the printedlayer on one side and a sensor layer on the other wherein the sensorlayer comprises a core layer, 35, comprising a cavity wherein thesensor, 36, is received in the cavity. It is most preferable that thecavity and sensor are approximately the same dimensions. A transparenttop layer, 38, is laminated to the sensor layer preferably by anadhesive layer, 37, such as an HAA or PSA layer. An optional layer, 39,may be provided if desired. The optional layer may comprise a scratchoff bar which may be printed or it may comprise a protective layer suchas a black PET. The printable layer is preferably a TCA (trichloroacetic acid) etched polyethylene terephthalate (PET) film with athickness of about 5 to 7 mil and printing on the exterior side. Theadhesive layers are preferably either PSA or HAA layers with HAA beingpreferred. The adhesive layers are preferably about 2 to 4 mils thickfor most adhesives. It is desired that the adhesive layers be as thin aspossible without compromise in adhesion. Certain adhesives may allow thelayer thickness to be lower. The core layer is preferably a Teslin® orArtisyn® layer. Teslin® is a dimensionally stable, highly filled, singlelayer, microporous film. It is polyolefin-based with 60% of its weightcomprised of non-abrasive filler and 65% of its volume comprised of air.Teslin® is available in various gauges from PPG Industries, Inc. Teslin®and Atrisyn® are the most preferred for demonstration of the presentinvention. Artisyn® is a uncoated, single layer, highly filledpolyolefin which contains approximately 50% non-abrasive filler byweight and about 60% air. Artisyn® is available at Protect-All PrintMedia, Inc. The core layer is preferably about 7 to 14 mils thick. Thecore layer can be printed if desired to provide color or information.The transparent top layer is preferably a PET film with a thickness ofabout 5-7 mils. If an optional cover sheet is desired a 2-sided adhesivefilm wherein the adhesive is either a PSA or an IAA can be applied tothe transparent layer with a black PET film laminated thereon.

The cards can be manufactured on line in a continuous way as exemplifiedin FIG. 4. In FIG. 4 rolls of different layers such as top and bottomlayers with an adhesive and core layer with sensing strip. In FIG. 4, aseries of films are provided on rolls and moved through a pair of niprollers to form a laminated layered structure. In one embodiment, abottom layer, 41, fed from a first roller, 42, comprises PET with anadhesive layer, preferably HAA, on one surface. The bottom layer is fedwith the adhesive layer interior to the PET film. A sensing layer, 43,fed from a second roller, 44, provides an alternating pattern of sensingstrip and core material. The sensing strip is preferably integral to thecore material and encased in a cavity therein such that the thickness ofthe layer is constant. Supra to the sensing layer is a top layercomprising a PET support with an adhesive layer, preferably HAA, coatedthereon. The adhesive is between the PET and sensing layer. A protectivelayer, 45, fed from roller, 46, preferably comprises a PET with a hotmelt adhesive. Supra the top layer is an optional, but preferred,pre-printed black protective film, 47, with a thin band of PSA tapethereon thereby allowing the protective film to be removed after use.The black protective film, 47, is fed by roller 48. The layers arebrought into layered arrangement and laminated into a single layeredstructure by a pair of nip rollers, 50, which are preferably heatedthereby resulting in the layered structure, 40, which is preferably cutinto the desired size.

A finished sensing layer is illustrated in FIG. 5. In FIG. 5, the corelayer has pre-printed scales, instructions, etc. Embedded therein aresensing strips. In the embodiment illustrated a blue sensing strip andred sensing strip are provided.

Schematic presentations of different ways dual-sensor SIRAD cards can bemade are shown in FIGS. 6-9.

In FIG. 6, the bottom layer is a 6-8 mil opaque PET film with writablebottom surface printed with instructions and about a 2 mil thick layerof HAA on the top. The sensing layer is a 10-14 mil white or opaque filmcomprising Teslin®, Artisyn® or PET with color reference bars printedthereon. Other information is printed on the top surface. If PET is usedit is preferable to have an HAA layer on each side. The top layercomprises a 6-8 mil transparent PET film with scratch-off opaque orblack bars printed on a top antiglare or satin surface. About 2 milthick layer of HAA is on the bottom. The protective layer is a 4 milthick black protective PET film with instructions printed on the top anda 2-3 mil thick and 3-4 mm wide HAA or PSA tape.

FIG. 7 illustrates schematically the process of the present invention.At step A, four discrete films, 1-4, are provided. Film 1 is a toplayer, film 2 is a PET layer, film 3 is a core layer and film 4 is abottom layer. The core layer, preferably a Teslin® (D layer, is die-cutto form a cavity the size of the sensing strip at Step B. The bottomlayer and core layer are laminated at step C. The sensing strip isinserted into the cavities formed in step B at step D. Layer 2 islaminated to the composite layer from step C at step E with the sensorthere between in the cavity. The top layer is laminated to the compositefrom step E and step F. As indicated in FIG. 7 each layer may haveprintings incorporated thereon.

FIG. 8 illustrates a five layer structure that may be formed into acomposite in a manner analogous to the described relative to FIG. 7. InFIG. 8, the bottom layer, A, comprises an opaque TCA-PET layer with athickness of about 2-5 mil. The bottom surface is preferably printedwith instructions preferably in black. A second bottom layer, B,preferably comprises a 2-5 mil thick PET film having an adhesive coatedat about 1-2 mil thickness on each side. The adhesive is preferably HAAor PSA. Layer C is the sensing layer comprising a 10-14 mil thick whiteopaque layer preferably selected from Teslin® ®, Artysin® or TCA-PETwith color reference bars and other printed information printed thereon.The layer has a cavity with a sensor in the cavity. Layer D ispreferably a 3-10 mil thick transparent layer which is preferably PET.Scratch-off opaque-black bars are printed on the top. The surface ispreferably an antiglare, or satin, surface. The layer has an adhesivelayer on the bottom which is preferably about 2 mil thick. The adhesiveis preferably HAA or PSA. Layer E is a top layer which is preferably a 4mil thick black PET film with instructions printed on the top. The layerhas a 2-3 mil thick and 3-4 mm wide adhesive preferably selected fromHAA and PSA.

FIG. 9 illustrates a six layer construction which would be prepared in amanner analogous to that described relative to FIG. 7. In FIG. 9, layerA is a transparent PET film with a thickness of about 4 mil. The filmhas a writable bottom surface and about 2 mil thickness layer of HAA orPSA adhesive thereon. Layer B is preferably a Teslin® ® layer which isabout 7 mil thick. The bottom surface is printed with instructions,preferably in black. Layer C is a PET film which is about 1 mil thickhaving adhesive layers on each side wherein each adhesive layer is about2 mil thick. The adhesive is preferably HAA or PAA. Layer D is thesensor layer and is preferably about 10-14 mil thick white or opaquelayer of Teslin® ® with color reference bars and other informationprinted on the surface. Layer E is preferably about a 4 mil thicktransparent PET film with scratch-off opaque black bars printed on thetop antiglare or satin surface. The bottom has about 2 mil thick layerof adhesive preferably selected from HAA and PSA. Layer F is about a 4mil thick protective layer of black PET film with instructions printedon top and a 2-3 mil thick and 3-4 mm wide HAA or PSA tape.

Examples of printing on the protective opaque, core and bottom layersfor SIRAD cards are shown in FIGS. 10-12.

FIG. 10 illustrates a representative printed protective opaque layerincluding instructions.

FIG. 11 illustrates a printed core layer with scales indicating theamount of radiation received and instructions for use.

FIG. 12 illustrates a printed bottom layer with instructions andlocations for filling in important information.

Top, core and bottom layers could be any material such a plastic, paperand metal. The preferred material is a plastic. They could be made fromnatural and synthetic polymers, such as polyolefins, polyvinyls,polycarbonate, polyester, polyamide, or copolymer and block copolymerssuch as ABS (copolymer of acrylonitrile, butadiene and styrene) andcellulose acetate. The most preferred materials are polyesters,polycarbonates, polyolefins, polyvinyls and copolymers such as ABS.These layers could be made from the same or different plastics.

The core layer can also be a self standing heat activated adhesive.

The thickness of the layer would depend upon the nature and utility ofthe card. The most preferred total thickness would be between 20-40 mils(500-1,000 microns).

Transparency or opaqueness of each layer would also depend upon theapplication. For cards such as SIRAD, it is required that the bottomlayer be opaque and the top layer be transparent. For other application,these layers could be either opaque or transparent.

The adhesive, or bonding layer, could be a pressure sensitive adhesiveor heat activated adhesive. For heat activated adhesives it isparticularly preferred that the adhesive have a melting point of lessthan 100° C. In order to make the cards tamper resistant, the preferbonding layer is heat activated adhesive or two component bondingmaterials, such as polyepoxy or polyurethane or those can be cured bycrosslinking. The preferred bonding layer for SIRAD cards will be lowmelting, especially if the sensing strip is affected by hightemperature. Heat activated adhesive is preferred as it makes the cardstamper resistant and provides stronger bond than that provided by apressure sensitive adhesive.

The process of assembling the different layers of the cards islamination.

A further simpler way is to mold core layer with cavities; core layerwith cavity and the bottom layer as one piece; or core layer with cavityand the bottom layer as one piece and further printed with requiredinformation on the bottom and color reference bars on the top.

Though the methods disclosed here can be used for making smart cards ingeneral, they can also be used for making SIRAD cards, both with one ormore sensing strips. The desired properties of the top, core and bottomlayers and processes are described below:

The top transparent layer can be PET, PETG (glycolated PET) or PVC(polyvinylchloride). Preferred is PET. The top surface is preferablytreated physically or chemically for antiglare and scratch resistance.It is preferred that the scratch resistance by at least equivalent tothe scratch resistance of PET fihn. It is most preferable to include UVabsorbance. UV absorbing PET film are commercially available. It ispreferred that the top transparent layer be highly transparent and clearwith no coloration such as yellowing since this may interfere with thedetermination of the color of the indicator. The top surface shouldstrongly bond with two sided PSA tape or HAA tape of about ¼ inch widthwith the black/opaque protective film. The bond with the core materialis preferably more than 10 lb/inch. The thickness is preferably 5-10mils (125-250 microns). If black or highly opaque scratch-off bars areused it is preferable that they pass a standard cross-hatch tape test inaccordance with a standard test such as ASTM D2197, D2248, D3454 orD5178. The top surface should be printable.

The middle core layers could be a plastic film, such as PVC, PET orpolyolefin (such as Teslin® or Artisyn®) with die-cut cavities forsensing strips. The film will require a bonding layer such as a heatactivated adhesive on each side. The layers are preferably bonded withthe bottom layer to create wells or cavities for the sensing strip(s).The layers preferably do not react with any component of the sensingstrip. The layers should not affect performance of the sensing strip.The layers should strongly bonded, preferably at 10 lb/inch or higher)with the top and bottom films. The layers should preferably be opaque.The layers should be printable for color reference bars and otherinstructions. It is preferable that the minimum thickness is that of thesensing strip.

A preferred core material is commercially available polyolefin membranelayer called Teslin® or Artisyn®. However, any other core material, suchas polyester PETG and PVC, which can provide good bonding with the topand bottom layers, can be used. The bottom material can be PET, PETG,PVC Teslin® or Artisyn®. The bottom surface is preferably writable withan average ball point pen. It is highly preferred that each card have adifferent serial number and corresponding bar code printed on the bottomlayer. The bottom material is preferably white and highly opaque. Thebottom material should strongly bond with the core material with abonding strength of preferably 10 lb/inch or higher. The preferredthickness is 5-10 mil.

EXAMPLES

The following Examples are illustrative of carrying out the claimedinvention but should not be construed as being limitations on the scopeand spirit of this invention. In the examples below the encapsulant is aradiation sensing strip described in patent application No. WO2004/077097 and WO 2004/017095 but it could be any other sensor,electronic device or any other encapsulant. Similarly, the process isexemplified with SIRAD cards but any other type of smart cards can bemade.

Example 1

Composites having the bottom opaque layer and the core layer with acavity for the sensing strip as shown in FIG. 1 were purchasedcommercially. This composite was made by the conventional method ofmaking credit card under high pressure and high temperature. The bottomlayer was printed with instruction similar to that shown in FIG. 12 anda set of color reference bars similar to that shown in FIG. 11. Thesensing strips were inserted and laminated with a UV absorbingtransparent film having a PSA layer. This card has a PSA layer which canbe peeled off.

Example 2

Using a color laser/toner printer made by Toshiba a 12 inch×18 inch 14mil thick Teslin®® film, available from PPG, Pittsburgh, Pa., wasprinted on the top with color reference bars and other informationsimilar to that shown in FIG. 11 and the back with information similarto that shown in FIG. 12. The Teslin® film had 21 images (3 rows of 7images each). The Teslin® film was then die-cut to create holes for thesensing strips. Die-cut Teslin® film was laminated with a 12 inch×18inch clear 7 mil polyester film having three mil layer of heat activatedadhesive using a heated roller laminator. The sensing strips wereinserted in the cavities and laminated with a transparent 7 milpolyester film with 3 mil of low melting (˜85° C.) heat activatedadhesive using a heated roller laminator. A 4 mil 12 inch×18 inchpolyester film screen printed with white ink with information similar tothat shown in FIG. 10 was laminated with a ¼ inch two sided adhesivetape. There was no bulge at the locations of the sensing strips. Thelaminated sheet was die-cut to make 21 cards 2⅛^(th) inch×3⅜^(th) inchwith rounded corners. The different layers of the cards were verystrongly bonded and they were tamper resistant.

Example 3

SIRAD cards were made using the procedure described in Example 2 exceptthat the bottom layer was an opaque 7 mil polyester film having a threemil layer of heat activated adhesive. The printing similar to that shownin FIG. 12 was on the bottom of the white film instead of on theTeslin®. There was no bulge at the locations of the sensing strips. Thelaminated sheet was die-cut to make 21 cards 2⅛^(th) inch by 3⅜^(th)inch with rounded corners. The different layers of the cards werestrongly bonded and they were tamper resistant.

Example 4

SIRAD cards were made using the procedure described in Example 3 exceptthat the bottom layer was an opaque 8 mil polyester film with printingon the back similar to FIG. 12 and the top layer was 8 mil clearpolyester film and the adhesive layers were transparent 2 mil selfstanding heat activated films. There was no bulge at the location of thesensing strips. The laminated sheet was die-cut to make 21 cards 2⅛^(th)inch by 3⅜^(th) inch with rounded corners. The different layers of thecards were very strongly bonded and they were tamper resistant.

Example 5

SIRAD cards were made using the procedure described in Example 3 exceptthat instead of Teslin® as a core layer, 10 mil polyester film etchedwith trichloroacetic acid was used. There was no bulge at the locationsof the sensing strips. The laminated sheet was die-cut to make 21 cards2⅛^(th) inch by 3⅜^(th) inch with rounded corners. The different layersof the cards were very strongly bonded and they were tamper resistant.

Example 6

SIRAD cards were made using the procedure described in Example 3 exceptthat the core layer was 6 mil polyester film with 2 mil heat activatedadhesive on each side and the top layer was 10 mil clear polyester filmprinted with color reference bar and bottom layer was 10 mil opaquepolyester film with printing on the bottom. There was no bulge at thelocations of the sensing strips. The laminated sheet was die-cut to make21 cards 2⅛^(th) inch by 3⅜^(th) inch with rounded corners. Thedifferent layers of the cards were very strongly bonded and they weretamper resistant.

1. A multi-layer smart card comprising a top layer, a core layer havingat least one cavity, an encapsulant in said cavity, a bottom layer andadhesive layers between said top layer and said core layer and betweensaid core layer and said bottom layer.
 2. The multi-layer smart card ofclaim 1 wherein said core layer is selected from polyolefins, polyvinyl,polycarbonate, polyamide, polyester and copolymers thereof.
 3. Themulti-layer smart card of claim 1 wherein said adhesive layer comprisesa material selected from a pressure sensitive adhesive and a heatactivated adhesive.
 4. The multi-layer smart card of claim 3 whereinsaid heat activated adhesive melts below 100° C.
 5. The multi-layersmart card of claim 1 wherein at least one layer selected from said toplayer, said core layer and said bottom layer is printed withinformation.
 6. The multi-layer smart card of claim 1 wherein saidencapsulant is a radiation sensitive device capable of monitoringradiation exposure.
 7. The multi-layer smart card of claim 1 furthercomprising a protective layer on said top layer.
 8. The multi-layersmart card of claim 7 wherein said protective layer is attached to saidtop layer by a pressure sensitive adhesive.
 9. The multi-layer smartcard of claim 1 further comprising at least one layer in one locationselected from between said top layer and said core layer and betweensaid bottom layer and said core layer.
 10. The multi-layer smart card ofclaim 1 further comprising a scratch-off bar.
 11. A process of makingsmart cards by inserting an encapsulant in a cavity of a core layer,sandwiching said core layer between a top layer and a bottom layer andlaminating with adhesives.
 12. A process of making of making smart cardsof claim 11 wherein said cavity is formed by a method selected fromdie-cutting, laser cutting and casting.
 13. A process of making a smartcard comprising the steps of: providing a core layer with a cavity;providing a bottom layer; laminating said bottom layer to said corelayer; inserting an encapsulant is said cavity; and laminating a toplayer to said core layer.
 14. The process of making a smart card ofclaim 13 comprising providing a cavity and said bottom layer as onepiece printed with instruction on a bottom and color reference bars on atop.
 15. The process of making a smart card of claim 13 wherein saidcore layer is a self standing heat activated adhesive.
 16. A process ofmaking a smart card comprising: providing a first layer; providing asecond layer wherein said second layer has at least one cavity;providing a third layer; inserting an encapsulant in said cavity;placing said first layer, said second layer and said third layer inlayered relationship; and fusing said layered relationship to form saidsmart card.
 17. The process for making a smart card of claim 16 furthercomprising an adhesive in at least one location selected from betweensaid first layer and said second layer and between said second layer andsaid third layer.
 18. The process for making a smart card of claim 17wherein said adhesive is selected from heat activated adhesive andpressure sensitive adhesive.
 19. The process for making a smart card ofclaim 16 wherein said inserting an encapsulant is said cavity is priorto said providing a third layer.
 20. The process for making a smart cardof claim 16 wherein said encapsulant is a radiation sensitive device.21. The process for making a smart card of claim 16 wherein said firstlayer and said second layer are laminated prior to said inserting anencapsulant in said cavity.
 22. The process for making a smart card ofclaim 16 wherein said cavity is formed by a method selected fromselected from die-cutting, laser cutting and casting.